Memory 4 - Signs and Symbols, Part I

Make your way towards the tower near the Hagia Sophia as marked on the map. Climb the tower the very top to find the mission marker and to start the mission.

When prompted, activate Eagle Sense and search for the Niccolo Polo symbols on the ground. When you've spotted the correct glyph (located in the mid-section of the Hagia Sophia rooftop), it will be marked on the GPS.

From there, use a Leap Of Faith to the bottom (or a parachute) and approach the marker to find the hidden item and to complete the mission.